Rotary pump or compressor



^ Feb. 18, 1936. w. w. wlOsHART ROTARY PUMP OR COMPRESSOR 2 sheets-sheet 1 Filed Feb. 14, 1934 Feb. 18, 1936. w. w. wlsHART 2,030,952

ROTARY PUMP 0R COMPRESSOR Filed Feb. 14, 1934 2 Sheets-Sheet 2 2fg 26 El/@nim mu/imam:

Patented Feb. ,18, 1936 UNITED STATES PAT-ENT f ori-ichV ROTARY PUMP` 0R COMPRESSOR William W- Wishart, Chicago, Iii., asaignor of 4 I one-half toAutomotive Maintenance Machinery Co., Chicago, lll., a corporation of Illinois Application February 14, 1934, serial No. 111Mo c claim. (ci. loa-121) My invention relates to rotary pumps or compressors of the partitioned crescent-chamber type. and has for its general object to provide animproved construction ci' high eiilciency, great durability and economical simplicity. In one of its aspects, certain more speciiic objects.- of my invention are to provide a pumpof the stated type particularly adapted for the handling ofrefrigerants and suitable for use in vhousehold refrigerators and the like where the compressor must work for long periods without attention, and where sustained high emciency, adequacy of sealing and of lubrication, minimization of wear. and .facility of upkeep-adjustment are particular desiderata, all of which are well attained in my novel construction.

In the drawingsi Figure'l is a longitudinal vertical section through one form of my compressor, with the shaft-carried parts in elevation save where broken away:

Fig. 2 is a vertical crass section on line l2---2 of Fig. 1:

Figs. 3, 4, and 5 are diagrams of the chamber` and-partition parts in different positions .of the cycle ofl rolling action;

Fig. 6 is a fragmentary end view of thevcheck valve arrangement, shown inV Fig. 1; Fig.'1 is a section on line l--l of Fig. 6;

Fig.8`isaviewsimilartoFig. lshowingamodi-- indicates in general the machine casing, one of- 4 which is rotatable relative to the other; the

machine shown in Fig. 1 `having the shaft II) and its connected parts vconstituting the stator assembly, with a casing II and its associated parts power driven and constituting the rotor assembly, while in the machine shown in Fig. 8,

these relations are reversed, the shaftbeingA driven and the casing structure being stationary. vvReferring to the construction shown in Fig. 1, I2 is a mounting base in which shaft I0 is tightly mounted and I3 is a cylindrical block tightly mounted on or integral with the shaft and constituting the machines piston-member. I4-

is the cylinder memberl of annular form, larger in its interior diameter than the diameter of the piston, to cooperate with the latter in substantial line contact, leaving the crescent-shaped working space I5 between them. I6 is a partition member connecting the cylinder and piston in 'suitable fashion topermit of oscillation of the cylinder relative to the piston, requisite for so-calied rolling progression of the contact line as the rotor is revolved. :Inthe specific construction shown, the partition I8 has a parti-cylindrical pintle-portion Il rockably engaging a socket Il 5 in the cylinder member Il and a flat sided blade portion I9 making close sliding flt in a slot 2l in the piston member Il to accomodate the osciiiatory displacement of the cylinder member as dia-l grammed in Figs. 3, 4 and 5.

10 The coacting casing .II is here shown as including side plates 22- and 23 having respective hubs 22' and 2l' in running engagement witliy the shaft, and an interposed camming shell 2| spacing the -side plates for *close vagainst the ends of the piston and cylinder members, said camming shell having its internal cam-l ming face 25 of circular form,;eccentric to shaft I0 and concentric to the'perimeter of the annularcylinder Il to compel oscillation of such cylinder 20 member during reiativerevolution of lthe-shaft I0 and casing II, a suitable roller bearing structure 26A being interposed between these parts and here shown' as of' well known construction in which muera :e1-protrude through a cage band 2s. 25 In the construction shown, tie bolts 30 tightly clamp the side plates against the camming shell 24, butthe bolt-receiving openings 3l through said shell are considerably oversire so that when` the nuts 32 are loosened, the weight of the shell 3o vmember will move the cylinder I4 into contact with the piston". Thus. any wear between' the pistonand cylinder may be taken up, andin the manufacture of .the--aiected parts the radiustolerances need not be diilicultly small.

In embodiments of my invention intended for use to compress various uids, such as refrigerants, very eifective safeguarding against fluid leakage, either out of the circulatory system or from the pressurer side of the compressor into 40 the suction side thereof, is especially desirable;

and also insurance of adequate lubrication is important, not only for mechanical emciency, but to insure proper oil-sealing of .the working-.cham-t ber parts, bearings, etc., and the construction 45 -shown in Fig. 1 is especially effective in these ret-- gards. Referring to Fig. 1, 34 indicates the fluid inlet passage of the machine extending from a coupling receptive opening 35 in bracket I2 and ducts 50.'

drilled in the shaft and piston to the suction -inlet 36 closely adjacent to partition member, I6 at `the appropriate side thereof-being the right sideV with the casing rotating in the arrow-indicated direction, Fig. 2`the longitudinal run of the pas.- 555 partitionIS, to afduct in a suitable quadrant of the shaft leading to the free end of the shaft.

where a check valve 33 may be provided, a supplemental portion of the outlet passage, indicated 'at 31', extending through another quadrant of the shaft and communicating with a iltting-receptive opening 40 in the bracket I2.

In the construction here shown, the check valve 33 comprises a slightly tensioned valve-leaf 42 coacting with a nipple 43 fitted into duct 31,` the area-difference between the valve-receiving or seating-surface of the nipple andits ilow-oriilce being larger orv smaller to give suchdiiferential effect as is desired for the intended utilization of the machine.

The casing I I provides a sealed c r 44 in which the check valve is accommodated and-into which ducts 31 and 31' open and in which, of course, any back. pressure against which the compressor works is always exerted.- Q

In the operation of the machine, relative rotation between the stator assembly andthe rotor assembly results in oscillation of the annular cylinder I4 with respect to, and in so-called rolling" line contact with, the cylindrical piston I3, under 30 the camming action of the camming shell 25 surrounding the cylinder, applied through the intervening roller-bearing structure 23, such cylinder oscillation creating a suction area between the clockwise-progressing contact line and the right 35 side of the pmtition' I6 and a pressure area between said'contact line andthe left side of the partition; check valve 39 permitting escape of the compressed iluid when it has attained sumcient pressure to open the valveL and back ilow 4p of fluid from the delivery duct 31' or sealed chamber 44 into the working chamber of the machine, either when the parts are passing dead center Iposition shown in Fig. 2 or, beforeuthe desired pressure has been created on the pressure side 45 of the machine, beingprevented by said check valve.

In the construction shown in Fig. 8, where the l shaft m is rotated as `by driving puney 4s, the

shaft ducts 34 and 31' may open to the circular lo channels 34* and 31* in the elongatedhub of the stationarycasing, into which the connection receptive openings 35 and 43 lead, and the sealed chamber 44 beyond the end of the shaft is merely a recess of the side-plate hub 23. 'Y

In Fig. 9, mv machine is disposed for operation on the vertical axis, with its casing member rotatable through connection of hub 23l with the drive shaft of motor 43, the stationary shaft ,I2 having its inlet and outlet ducts 34 and 31' open- 60 ing through the connection receptive holes of the shaft supporting block I2', and the assembly unit being mounted in any suitable frame 41.

'Ihe constructions shown inFigs. 8 and 9, having no special provision for oiling, may most eiIec- 65 tively be used in pumping liquids having a lubrieating effect onfor compressing fluids that, asin the instance of some refrigerante, normally carry a suitable percentage of lubricant.

' In the construction shown in Figfl, the sealed 'I0 chamber 44 beyond the end vof shaft II ,is pro- 75 ing is rotated, is centrliugally thrown to the pea,oso,osa g A i :mm1-y of. the chamber, where it has lime tendency to admix with the iluid being passed through the'machine; part of this lubricant passing down the upstanding o il pipe 52, which reaches nearly -to the periphery of the 'chamber and delivers its oil to a duct 33 extending within a fourth quadrant of the shaft to vents 54 vfor oiling the rotor hubs; and oil also having access to the roller bearings through opening 56 in the side plate 23; adequacy of oil supply being in this instance further insured by the fact that the sealed chamber is subject to whatever back pressure the compresser -is working against.

For eiiectually ensealing the bearing hub 22',

I preferably employ a bellows seal construction 53, in .which the expansive pressure of the metallic bellows 53 is exerted between the-plates il and 6I connected therewith, the former being mounted on 'the hub 22' and the latter making sealing contact with the end of supporting bracket I2, a spring 62 being mounted between plates 30 and 6|, if desired, to enhance the sealing pressure.

In constructions, as shown inFigs. 1 and 9, wherein the casing is the. rotor, it may be balanced, if desired, to compensate for diiferences in thickness oi? shell section 24, in any simple fashiomas by recessing the part 24 as at 63, Fig. 2, or balancingly varying the thickness of the fan vanes 34 on the rotor. v

It will be observed that the machine is well adapted to deliver quite high pressure with excellent eiliciency. The working chamber I 4, lccated relatively near the center of the machine,

' has'large metallic masses surrounding it for rapid dissipation of the heat of compression, which heat dissipation may be augmented, where the shell is rotated; by self-circulation of air by suitable vanes 64 angularly disposed to fan the air in a direction generally longitudinal of the casing; and the camming surface 25 of the oscillating means for the cylinder operates at a low wedging angle, while the rubbing side-contacts between the piston I3 and the side plates of the in Fig. 1, my compressor'is particularly adapted for use in sealed-inrefrigerator systems, such as are now commonly' employed in household refrigerators.

1. In amachlne of the character described, a shaft support, -a stator assembly and a rotor assembly, one of said assemblies comprising a shaft having one end mounted in said support and its other end unsupported, a cylindrical piston member carried by said shaft, a surrounding annular cylinder member arranged for line contact with said piston member to leave a working space therebetween, and a partition constantly connecting said members and permitting oscillation of said cylinder member with respect to said plston member; and the other assembly comprising side plates coasting with the ends y of the piston and cylinder members and a peripheral portion having an internal cammina' surface for progressively oscillating said cylinder member during relative rotation of the two a,oso,osa

an external portion of such assembly overlying the unsupported end of said shaft being removable and containing a chamber in which a portion of said shaft is exposed: said shaft having an inlet passage and an outlet passage therein, each extending to and accessible at the supported end-portion of the shaft, said inlet passage opening at `its other end to the working space near one side of the partition, and said outlet passage comprising two portions. one of which opens from the working space near the other side of said partition through the chamber-exposed portion of said shaft and the other of which extends from said chamber to the supported end-portion of said shaft: and a `check valve mounted on said shaft in position to be exposed for service access upon removal of said removable portion of -the aforesaid other assembly, said valve controlling the first ymentioned portion of said outlet passage. A,

2. In a machine 'of the character'described, a shaft support, a stator assembly and a rotor assembly, one of said assemblies comprising a shaft mounted in said support and cal'ryins a cylindrical piston member, an annular cylinder member arranged for line contact with said piston to leave a crescent-shaped working space therebetween, anda partition constantlylconnecting said members and permitting oscillation of said cylinder member with respect to said piston member, and the other assembly comprising side plates coacting with the ends of the piston and cylinder members and a peripheral portion having an internal camming surface for progressively oscillating said cylinder member during relative rotation of the two assemblies and also having a removable external structure enclosing a chamber to which the end of said shaft is exposed, said first-mentioned assembly having-an inlet passage opening to said working space near one side of said partition and an outlet passage opening from said space near the other side of said partition and including shaft-contained ducts respectively connecting the working space to the chamber and the chamber to an external delivery opening: and a check valve in said chamber mounted on the end of said shaft to be exposed when said external structure is removed and controlling its mst-mentioned duct.

3. In a machine of the character described, a shaft support, a stator assembly and a rotor assembly, one of said assemblies comprising a shaft mounted in said support, a cylindrical piston member carried by said shaft, a surrounding annular rotor member arranged for line contact with said piston member, and a partition constantly connecting said members and permitting oscillation of one thereof with respect to the other; and the other assembly comprising sideplates contacting with the ends of the piston and cylinder members and a peripheral portion havlng an internal camming surface for progressively oscillating said cylinder member during relative rotation of the two assemblies, and the aforesaid other assembly having a removable external portion overlying a chamber in which the end of the shaft is exposed; the aforesaid one assembly having an inlet passage opening to the working space near one side of the partition and an outletpassage opening from the work space near the other side of the partition and through the chamber-exposed end of said shaft and from said chamber through said shaft tothe exterior of the machine; and a check valve comprising a .spring valve mounted on nipple mounted in the end of `the passage-opening from said shaft to said chamber. and a fiatthe end of said shaft and cooperating with said nipple, in position to be exposed for service-access upon removal of said external portion of said other assembly,

4. In a machine of the character described. a shaft support. a stator assembly and arotor assembly, one of said assemblies comprising a shaft mounted in said support. a cylindrical piston member carried by said shaft, a surrounding annular cylinder member arranged for line contact with said piston member, and/a partition constantly -connecting said members and permitting oscillation of one thereof relative to the other; and the other assembly comprising side plates coacting with the ends of the piston and cylinder members, a peripheral portion having an internal camming surface for progressively oscillating said cylinder member during relative ,rotation of the two assemblies and the aforesaid other assembly having a removable, external lubricantchamber portion into which the end of the shaft is exposed; the aforesaid one assembly having an inlet passage through its shaft opening to the working space near one side of the partition and to the exterior of the machine, and an outlet passage opening from the working space near the other side of said partition and through the end of said shaft to said lubricant-chamber and thence through said shaft to the exterior of the machine; said shaft having an oil duct therein opening .at one end to said lubricant-chamber and having openings for delivering oil to relatively m'ovable surfaces of the machine between said stator assembly and said rotor assembly; and a check valve in said lubricant chamber mounted on the end of said shaft to be exposed when said external structure is removed and controlling communication between said chamber and said outlet passage from the working space between the two assemblies.

' 5. In a machine of the character described, a

rotatable casing, a piston member and an annular cylinder member therein leaving a crescentshaped working space between them and relatively oscillatable by casing rotation, a partition constantly connecting said cylinder and piston members and permitting relative oscillation thereof, and a shaft extending longitudinally through said piston member and whereon said casing rotates; said rotatable casing including at the end thereof overlying the shaft-end a lubricant chamber wherein the lubricant is centrifugally displaced by casing rotation; saidv machine havlng an inlet passage to and an outlet passage from said working space between the relatively oscillatable members with said outlet passage opening through said shaft to said lubricant chamber and said shaft having also a lubricant passage opening from said end of the shaft and into bearing surfaces between said shaft and machine-parts rotatable thereon; a check valve mounted on the end of said shaft for controlling the outlet-passage through said shaft to prevent back ow of lubricant into the working space in the machine and to maintain the lubricant; chamber under fluid pressure; and an oil pipe connected to said lubricant passage of the shaft and extending thence into the perimetral portion of said lubricant chamber.

6. In a machine of the character described, a shaft support, a stator assembly comprising a shaft mounted in said support and carrying` a cylindrical piston member, an annular cylinder member arranged for line contact with said piston, and a partition constantly connecting said members and permitting oscillation of said cylinder member with respect to said piston member; a rotor assembly comprising side plates ooacting with the endsnof the piston and cylindermembers and a peripheral portion having anv internal camming surfacefor progressively oscillating said cylinder member during relative rostructure having an inlet passage opening to theworking space between the cylinder and piston near one side of said partition and an outlet passage opening to said space near the other amano side of said partition and including shaft-contained ducts respectively connecting the working space to the lubricant chamber at the end of,said shaft and connecting said chamber to an external delivery opening, and a check valve in said chamber mounted on the end of said shaft to b'eexposed when'said casing is removed; said shaft also having` a lubricating'duct extending from the shaft-end into communication' with.

bearing surfaces between the stator and rotor, and an upstanding oil pipe'reaching from the last duct at the shaft-end into theperipheral portion of said chamber in an area to which the oil is centrifusally forced when the rotor is rapidly rotated and whence lt is delivered into said pipe with the aid of the uidpressure within said lubricant chamber. -j

` WILLIAM W. WISHART. 

